1. Field of the Invention
This invention relates generally to a measuring instrument, and more particularly to a self-locking-and-measuring ruler having many measures of notched scales for the drawing of parallel lines at precise intervals.
2. Description of the Prior Art
Problems and difficulties are being encountered in providing suitable means for measuring distances so as to properly locate lines on business forms, especially computer-printout forms. At present, it is very difficult, no matter how carefully a sheet is pre-measured, for the desired lines to fall exactly on the measured marks. If only one line is inaccurately drawn, it often results in additional uneven spaces, thus compounding the error in any given measured length. The measuring and placing of lines on computer-printout sheets is very critical due to the accuracy of the printout itself. Hence, there is no room for error.
There are various types of known ruling devices, none of which is believed to have the particular features as herein disclosed in the present application. Many of the known devices have inherent features that restrict their use, and they are often not as accurate as they were intended to be for measuring purposes. Also, some devices are complicated to operate and expensive to maintain.
As examples of related devices, one may refer to the following United States patents:
U.S. Pat. No. 245,726 relates to a T-square for a school slate on which lines can be drawn.
In U.S. Pat. No. 419, 640 a glass-cutting-and-drawing frame is disclosed wherein two edges of the frame are provided with notches.
U.S. Pat. No. 2,439,291 discloses a set-shift, parallel, ruling device which includes a rack and pinion arranged between the base member and the straight edge.
A combined drill guide and inspection device is disclosed in U.S. Pat. No. 3,145,589.
However, none of the above patents provides a means for establishing an accurate measuring and ruling for computer-printout sheets.